Broadcast 6000 User manual

Revision A07, 14 November 2005
Symetrix part number: 5360000A05
Subject to change without notice.
Copyright 2002-2005, Symetrix, Inc. All rights reserved.
AirTools™ is a registered trademark of Symetrix, Inc.
All other trademarks referenced in this User’s Guide are the property of their
respective holders.
Mention of third-party products is for informational purposes only and consti-
tutes neither an endorsement nor a recommendation. Symetrix assumes no
responsibility with regard to the performance or use of these products.
Under copyright laws, the content of this User’s Guide remains the property
of Symetrix, Inc.
6408 216th St. SW, Mountlake Terrace, WA, USA • Tel [phone] • Fax [phone] • Web www.airtoolsaudio.com
M
6000 Broadcast Audio Delay
User’s Guide

6000 Broadcast Audio Delay
User’s Guide
PAGE i
1. Read these instructions.
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with dry cloth.
7. Do not block any ventilation openings. Install only in
accordance with the manufacturer’s instructions.
8. Do not install near any heat sources such as radiators,
heat registers, stoves, or other apparatus (including
amplifiers) that produce heat.
9. Do not defeat the safety purpose of the polarized or
grounding-type plug. A polarized plug has two blades
with one wider than the other. A grounding type plug
has two blades and a third grounding prong. The wide
blade or the third prong are provided for your safety. If
the provided plug does not fit into your outlet, consult an
electrician for replacement of the obsolete outlet.
10.Protect the power cord from being walked on or pinched
particularly at plugs, convenience receptacles, and the
point where they exit from the apparatus.
11. Only use attachments/accessories specified by the
manufacturer.
12.Use only with the cart, stand, tripod, bracket,
or table specified by the manufacturer, or
sold with the apparatus. When a cart is used,
use caution when moving the cart/apparatus
combination to avoid injury from tip-over.
13.Unplug this apparatus during lightning storms or when
unused for long periods of time.
14.Refer all servicing to qualified service personnel. Servic-
ing is required when the apparatus has been damaged
in any way, such as power-supply cord or plug cord is
damaged, liquid has been spilled or objects have fallen
into the apparatus, the apparatus has been exposed to
rain or moisture, does not operate normally, or has been
dropped.
AVIS:
NE PAS OUVRIR
Il ne se trouve a l’interieur aucune piece pourvant entre reparée l’usager.
SEE OWNERS MANUAL. VOIR CAHIER D’INSTRUCTIONS.
S’adresser a un reparateur compétent.
RISQUE DE CHOC ELECTRIQUE
No user serviceable parts inside. Refer servicing to qualified service personnel.
CAUTION
WARNING:
TO REDUCE THE RISK OF FIRE OR
ELECTRIC SHOCK DO NOT EXPOSE
THIS EQUIPMENT TO RAIN OR MOISTURE
DO NOT OPEN
RISK OF ELECTRIC SHOCK
The lightning flash with arrowhead symbol within an equilat-
eral triangle is intended to alert the user of the presence of
uninsulated “dangerous voltage” within the product’s enclo-
sure that may be of sufficient magnitude to constitute a risk
of electric shock to persons. The exclamation point within
an equilateral triangle is intended to alert the user of the
presence of important operating and maintenance (servic-
ing) instructions in the literature accompanying the product
(i.e. this User’s Guide).
CAUTION To prevent electric shock, do not use the
polarized plug supplied with the unit with any extension
cord, receptacle, or other outlet unless the prongs can be
fully inserted.
Power Source. AirTools 6000 hardware uses a switch-
ing power supply that automatically adjusts to the applied
voltage. Ensure that your AC mains voltage is somewhere
between 100-240 VAC, 50-60 Hz. Use only the power cord
and connector specified for the product and your operat-
ing locale. A protective ground connection, by way of the
grounding conductor in the power cord, is essential for safe
operation. The power connector shall remain readily acces-
sible and operable once the unit is installed.
User Serviceable Parts. There are no user
serviceable parts inside the AirTools 6000. In case of
failure, customers inside the U.S. should refer all servicing
to the Symetrix factory. Customers outside the U.S. should
refer all servicing to an authorized AirTools distributor.
Distributor contact information is available online at www.
airtoolsaudio.com.
iImportant Safety Instructions

6000 Broadcast Audio Delay
User’s Guide
PAGE ii
Contents
1 Introduction ______________________________________________________ 1
2 Summary Product Description ______________________________________________________ 2
Front panel view ................................................................................................ 2
Rear panel view ................................................................................................ 3
3 Installation ................................................................................................ 4
AC line connection ................................................................................................ 4
Mounting in an equipment rack ................................................................................................ 4
Analog audio input connections ................................................................................................ 4
Analog audio output connections ................................................................................................ 5
Signal level ................................................................................................ 5
Typical system block diagram ................................................................................................ 5
Remote control & indicators connector ................................................................................................ 6
Automation connector ................................................................................................ 6
Menu tree ................................................................................................ 6
4 Operation ______________________________________________________ 8
Operational status ................................................................................................ 8
INPUT/OUTPUT LEVEL (dB) display ................................................................................................ 8
The START button ................................................................................................ 8
The EXIT button ................................................................................................ 8
The COUGH button ................................................................................................ 9
The DUMP button ................................................................................................ 9
The A1 through A4 relay status LEDs ................................................................................................ 9
The DELAY time (seconds) display ................................................................................................ 9
5 Troubleshooting ______________________________________________________ 10
Solutions to common problems ................................................................................................ 10
Less common problems ................................................................................................ 10
6 Warranty and Service ______________________________________________________ 11
The AirTools™ Limited Warranty ................................................................................................ 11
Limitation of Liability ................................................................................................ 11
Servicing the 6000 ................................................................................................ 12
Return authorization ................................................................................................ 12
In-warranty repairs ................................................................................................ 12
Out-of-warranty repairs ................................................................................................ 12
Appendices
A Specifications ______________________________________________________ 13
Architects and engineers specifications ................................................................................................ 13
Technical specifications ................................................................................................ 13
B Remote Indicator & Control Interface wiring ______________________________________________________ 14
Remote panel switch pinouts ................................................................................................ 14
Remote panel LED indicator pinouts ................................................................................................ 14
Typical remote panel switch wiring ................................................................................................ 15
Typical remote panel LED wiring ................................................................................................ 15
C Automation wiring ______________________________________________________ 16
Automation connector pinout ................................................................................................ 16
D Block Diagram ______________________________________________________ 17

6000 Broadcast Audio Delay
User’s Guide
PAGE 1
Thank you for your purchase of the AirTools™ model 6000 Broadcast Audio Delay, engineered by Symetrix. The
6000 has been designed to give broadcasters unequaled performance combined with ease of use and reliability.
This manual will guide you through the installation and operation of the 6000, and provide valuable tips on how to
interface with other equipment in your studio or control room.
The 6000 gives the host or producer of a talk show the power to prevent the broadcast of unwanted profanities
or comments from guests, hosts or telephone callers. As the program begins, the 6000 gradually and unobtru-
sively delays or "stretches out" the program until up to 40 seconds of 20 kHz bandwidth stereo audio is stored in
memory. When a person says something the host or producer does not think appropriate for the broadcast, he or
she presses the DUMP button and a user preset length of memory is cleared, thereby preventing the unwanted
audio from reaching the airwaves. Meanwhile, the host releases the offending caller from the telephone line and
proceeds with the program. After the DUMP button has been pressed, the 6000 automatically begins to stretch
(time expand) the program audio again until the user preset length of delay is attained.
Several minutes in advance of the end of the talk show, the host or producer presses the EXIT DELAY button and
the 6000 begins to time compress the program audio until there is nothing left in the 6000’s memory (zero sec-
onds delay). At this point the program is back in "real time."
A unique feature of the 6000 is the COUGH button, which allows the host to make impromptu interruptions in
the program for up to 40 seconds while keeping the audience unaware of the break. When the COUGH button
is pushed, the 6000 plays from memory while the button is held in. As soon as the button is released, the 6000
automatically begins to refill the memory. The host can cough, have a quick drink of water, or make a comment to
the producer or engineer without any perceptible program interruption.
The 6000 uses the latest in delta-sigma conversion technology coupled with advanced digital signal processing
(DSP) algorithms. This combination produces a product that meets or exceeds the highest broadcast standards in
terms of low noise, low distortion, and superb signal processing.
The 6000's logical, easy to use control panel holds no hidden surprises. The product is easy to learn and simple
to use. In the sections that follow you'll find information on installation, operation, and specific applications of the
6000. We follow this with a troubleshooting guide, warranty and service information, and detailed specifications.
As with all Symetrix engineered products, the 6000 has been designed and built to the highest standards of the
broadcast industry. Our company is committed to excellence in product design, manufacturing, and service.
Please do not hesitate to contact us with your questions or comments.
Terms
Several notational conventions are used in this manual. Some paragraphs may use Note, Caution, or Warning as
a heading. These headings have the following meaning:
Note Identifies information that needs extra emphasis. A Note generally supplies extra information to
help you to better use the 6000.
Caution Identifies information that, if not heeded, may cause damage to the 6000 or other equipment in
your system.
Warning Identifies information that, if ignored, may be hazardous to your health or that of others.
In addition, certain typefaces and capitalization are used to identify certain words. These are:
CAPITALS Controls, switches or other markings on the 6000's chassis.
Boldface Strong emphasis.
1Introduction

6000 Broadcast Audio Delay
User’s Guide
PAGE 2
This chapter provides a basic overview of the 6000 by describing the input and output connections, power con-
nection, operating controls, front panel LED indicators, and the remote indicator and control interface. Use this
information to acquaint yourself with the product. Chapter 4 (Installation) gives details on installing the 6000 in
your system and Chapter 5 (Operation) gets into specific applications and uses of the 6000 in detail.
Front panel view
2Summary Product Description
• The BYPASS button places the 6000 in either BYPASS or OPERATE modes. In BYPASS mode the incoming sig-
nals are directly routed (via relays) to the 6000's outputs, thereby bypassing any internal circuitry. In addition, the
digital I/O is relay bypassed. In BYPASS mode, the front panel and remote controls have no effect on the opera-
tion of the 6000. In OPERATE mode, the incoming signals are processed through the 6000’s analog and digital
circuitry, and all front panel and remote controls are fully functional.
• The PREVIOUS button displays the previous menu of the 6000’s menu setup hierarchy in the LCD display.
• The NEXT button displays the next menu of the 6000’s menu setup hierarchy in the LCD display.
• The HOME button returns the 6000’s LCD DISPLAY to the default operating screen which shows the following
information:
1. The top line of the LCD DISPLAY shows the input or output levels for audio channels 1 and 2. Each is
labeled with a numeral 1 or 2 respectively to the left. A bar graph meter will display to the right of each
numeral. Each bar graph increment represents 1 dB of signal for a peak level metering range of -40 to 0
dBfs.
2. The bottom line of the LCD DISPLAY shows the current operating status of the 6000. For example, 6000
BYPASSED, DELAY REMOVED, ADDING DELAY TIME, REDUCING DELAY TIME, WAITING FOR
RELEASE, MUTED, or MAXIMUM DELAY.
• The ADJUST knob scrolls through the available parameters to each setup menu item.
• The LCD DISPLAY shows the current menu item in the setup menu hierarchy as well as its current setting. It also
shows the ‘home’ screen as described under HOME (see above).
• The A1 through A4 LEDs show the state of the four internal relays used for delay automation. The LEDs will be off
when the relays are unenergized, green when energized and red when cued to be energized. Further description
of this feature is provided in chapter 5.
• The DELAY numerical readout shows the length of delay time built up by the 6000 in tenth of a second incre-
ments.
• The EXIT DELAY button initiates the gradual reduction of delay time. Once this button is pressed, assuming no
other control button is subsequently pressed, the 6000 will proceed to incrementally reduce delay time until a zero
delay is achieved.
• The START DELAY button initiates the gradual increase of delay time. Once this button is pressed, assuming no
other control button is subsequently pressed, the 6000 will proceed to incrementally increase delay time until a
user-determined preset second delay is achieved up to a possible full 40 seconds.
• Pressing the COUGH button pauses the incoming signal while allowing the output signal to play (uninterrupted)
from the 6000’s memory. The 6000 will continue to play from memory for so long as the button is pressed. When
the COUGH button is released, the 6000 resumes recording into memory and "splices out" the silence created
while the button was pressed. The 6000 then begins to rebuild the delay time used while the COUGH button was
pressed. The listener will be aware of a program interruption if and only if the button is held for a time exceeding
the time in memory, in which case the input is muted.
• Pressing the DUMP button erases a user-determined portion of the 6000’s delay memory. The 6000 will then pro-
ceed to splice back together everything except the erased audio. Next, if no other control button is subsequently
pressed, the 6000 will proceed to incrementally increase delay time until the user-determined second delay is
again achieved. See chapter 5 for further explanation of the DUMP function and its delay length settings.

6000 Broadcast Audio Delay
User’s Guide
PAGE 3
Rear panel view
• The AC INPUT connector accepts nominal AC power sources of 100 - 240 volts [see Appendix A (Specifica-
tions) for voltage tolerance ranges]. See chapter 4 (Installation) for details on the detachable (IEC) power
cable.
• The REMOTE CONTROL AND INDICATOR interface provides a way to connect to the AirTools RC-6000 or a user
supplied remote control and/or indicator panel. See Appendix B for details.
• The AUTOMATION interface provides a way to interface with the four internal relays used for delay automation.
See Appendix C for pinout.
• The ANALOG OUTPUT LEFT and RIGHT audio connectors are electronically balanced, line level, low impedance
outputs. Pin 1 is ground. Pin 2 is high. Pin 3 is low.
• The ANALOG INPUT LEFT and RIGHT audio connectors are electronically balanced, line level, bridging inputs.
Pin 1 is ground. Pin 2 is high. Pin 3 is low.
6000 BROADCAST AUDIO DELAY
100-240 VAC
50-60Hz
15 WATTS
MAXIMUM
MANUFACTURED BY SYMETRIX, INC. MTLK TERR, WA USA THIS UNIT CONTAINS NO USER SERVICEABLE PARTS.
Engineered By
www.airtoolsaudio.com
FABRIQUÉ AUX E.-U. PAR SYMETRIX, INC. MTLK TERR, WA
PAS DES ELEMENTS SERVIABLE PAR UTILISATEUR
25
AUTOMATION
REMOTE CONTROL & INDICATORS
1
1
25
LEFTRIGHT
ANALOG OUT
LEFTRIGHT
ANALOG IN

6000 Broadcast Audio Delay
User’s Guide
PAGE 4
AC line connection
A sticker on the rear of the unit indicates the nominal voltage setting for the unit as it left the Symetrix factory. If
this does not correspond to the voltage setting for your locale then do not attempt to apply power to the 6000.
Instead, return the unit to your local Symetrix distributor for modification.
The 6000 is shipped from the Symetrix factory with a detachable AC power cable (IEC standard) included.
Depending on the intended destination, the power plug is either the US type (intended for 117 VAC use), or the
Europlug type. If the power cable's plug is not right for your locale, then please contact your local Symetrix dis-
tributor for the proper cable.
Once you have determined that the 6000’s operating voltage matches that of your locale and you are ready to
begin, follow these steps:
Plug the socket end of the power cable into the recessed AC power receptacle on the back of the 6000.
Plug the other end of the power cable into a three-hole grounded outlet or power strip.
3Installation
1
2
WARNING The 6000 is intended to be electrically grounded. It has been provided with a three-wire grounding
plug - a plug that has a third (grounding) pin. This plug will fit only a grounded AC outlet. This is a safety feature. If
you are unable to insert the plug into the outlet, contact a licensed electrician to replace the outlet with a properly
grounded outlet. Do not defeat the purpose of the grounding plug!
Mounting in an equipment rack
The 6000 occupies one rack space (1U) in a standard equipment rack with a width of 19" (48.3 cm), a depth of
7.8” (19.8 cm), and a height of 1.75” (4.45 cm). Allow at least 4” (10.16 cm) behind the unit for the protrusion of
connectors. We recommend you take care not to mount the 6000 next to devices that emit large electromagnetic
fields, such as audio power amplifiers. To do so may comprise the noise performance of the 6000. The 6000 has
been designed to conform to mechanical guidelines as described in EIA Standard RS-310-C and IEC Recommen-
dation 297.
Analog audio input connections
The 6000’s audio input connections are via standard female XLR jacks located on the rear panel. For optimum
system performance we recommend that the 6000 be connected to balanced signal sources. If this is not practical
in your situation, then you may connect to unbalanced sources. The following diagram illustrates recommended
cable wiring practices.
1
3
2
Male XLR
Male XLR
Pin 1=Ground
Pin 2 = High
Pin 3 = Low
1
2 3
Pin 3 = Low
Pin 2 = High
Pin 1=Ground
2
1 3
TIP
RING
S
LEEVE
Sleeve = Ground
Ring = Low
Tip = High
Male 1/4" Tip-Ring-Sleeve Plug
Female XLR
Pin 1=Ground
Pin 3 = Low
Pin 2 = High
Analog Source 6000 Analog Input

6000 Broadcast Audio Delay
User’s Guide
PAGE 5
Analog audio output connections
The 6000’s audio output connections are via standard female XLR jacks located on the rear panel. For optimum
system performance we recommend that the 6000 be connected to balanced devices. If this is not practical in
your situation, then you may connect to unbalanced devices. The following diagram illustrates recommended
cable wiring practices.
3 1
2
TIP
Pin 3 = Low
Pin 2 = High
Pin 1=Ground
Male XLR
Tip = High
Male 1/4" Tip-Ring-Sleeve Plug
RING
S
LEEVE
Sleeve = Ground
Ring = Low
3 2
1
2
3
Pin 2 = High
Pin 3 = Low
Pin 1=Ground
Female XLR
Pin 1=Ground
Female XLR
1
Pin 3 = Low
Pin 2 = High
6000 Output Destination device input
Typical system block diagram
In most broadcast applications it is recommended that the 6000 be connected between the station's on air con-
sole and the station's audio processing equipment. In other words, the console's main stereo (or mono) output
bus should connect to the 6000’s inputs, and the 6000’s outputs should feed the "down stream" signal processing.
As discussed in Chapter 5 (Operation), the 6000 will automatically remove itself from the signal path when not
in use.
Signal Levels
The 6000 has been designed to operate at standard nominal broadcast signal levels of either 0 VU = +4 dBu or
0 VU = +8 dBu. To provide even more flexibility, the 6000 can also operate at -10 dBu and 0 dBu. The 6000’s
operating level can be adjusted by navigating to the NOMINAL INPUT and/or OUTPUT LEVEL pages in the setup
menus on the LCD display. A full discussion of the setup menus can be found on page 8.

6000 Broadcast Audio Delay
User’s Guide
PAGE 6
Remote control & indicators connector
This DB-25 connector allows you to remotely control the EXIT DELAY, START DELAY, COUGH and DUMP
functions of the 6000. You can also remotely view the status items DELAY INACTIVE, DELAY ACTIVE, HALF
delay accumulated and WHOLE delay accumulated. This connector interfaces directly with the AirTools RC-6000
Remote Control. Alternatively, you can use the pinout provided in Appendix B to wire your own remote and indi-
cators.
Automation connector
This DB-25 connector provides a way to interface with the four internal relays used for delay automation. The
6000 has four internal relays that may be independently used to control station automation events. The relay clo-
sures (outputs) are triggered by input closures that can be either manual (a momentary switch closure) or electri-
cal (TTL logic low). When an input closure takes place the audio entering the delay at that moment is ‘tagged’.
When the tagged audio reaches the output of the delay it’s corresponding relay closes for a time equal to the
length of the input closure.
A typical purpose for automation would be with the use of sync pulses provided by a nationally syndicated broad-
cast that is being relayed by a local station. The sync pulses can be used to automate the start and exit for the
6000’s delay. Another use would allow for a DJ to automate the exit of the delay to coincide with a commercial
break allowing the DJ to go on break without having to wait for the delay exit in real time. See Appendix C for
pinout.
Menu tree
HOME - displays the input/output levels for audio channels 1 and 2 on the top line in a bar graph fashion and dis-
plays the current operating status of the 6000 (BYPASSED, DELAY REMOVED, ADDING DELAY TIME, REDUC-
ING DELAY TIME, WAITING FOR RELEASE, MUTED, or MAXIMUM DELAY) on the bottom line. You can get to
this default display at any time by pressing the HOME button.
The following table illustrates the 6000’s menu tree with the menus and their options listed in the order that they
would appear if you were to advance through the menu tree using the NEXT button.
MENU OPTION
NOMINAL INPUT LEVEL -10 dBu
+0 dBu
+4 dBu
+8 dBu
NOMINAL OUTPUT LEVEL -10 dBu
+0 dBu
+4 dBu
+8 dBu
DELAY TIME 0.0 to 40.0 SECONDS (in 0.1 second increments)
DUMP LENGTH FIFTH
FOURTH
THIRD
HALF
WHOLE

6000 Broadcast Audio Delay
User’s Guide
PAGE 7
MENU OPTION
ALGORITHM
DELAY RATIO 10:1 to 40:1 Ratio controls the balance of delay build/exit
speed vs. overall audio quality.
(10:1 = fastest, 40:1 = best quality)
BARGRAPH MODE PRE DELAY
POST DELAY
AUTOMATION TRIM EARLY: 300 mS
EARLY: 270 mS
EARLY: 240 mS
EARLY: 210 mS
EARLY: 180 mS
EARLY: 150 mS
EARLY: 120 mS
EARLY: 90 mS
EARLY: 60 mS
EARLY: 30 mS
CURRENT DELAY
LATE: 30 mS
LATE: 60 mS
LATE: 90 mS
LATE: 120 mS
LATE: 150 mS
LATE: 180 mS
LATE: 210 mS
LATE: 240 mS
LATE: 270 mS
LATE: 300 mS
GAP DETECT Waits for gaps or
pauses in speech and
then splices audio.
Minimal delay arti-
facts.
Very fast delay build or
exit times with speech
only program when known
maximum build and exit
times are not required.
GAP DETECT
& CATCH UP
If gaps do not natu-
rally occur then
splicing is forced.
Some audible splice
artifacts.
Use for building and
exiting delay with music
+ speech when known maxi-
mum build and exit times
are required.
CONTINUOUS Continuously forces
splicing regardless
of program content.
Some audible splice
artifacts.
Use for building and
exiting delay with music
only when known maximum
build and exit times are
required.
PITCH SHIFT Uses gradual, subtle
pitch shifting
instead of splic-
ing to increase or
decrease delay.
Use with music or music +
speech when minimal arti-
facts are required. Build
and exit times are pre-
dictable.

6000 Broadcast Audio Delay
User’s Guide
PAGE 8
This section describes in more detail the 6000’s front panel controls and indicators.
Operational status
The BYPASS button places the 6000 in either BYPASS or OPERATE modes. In BYPASS mode the incoming
analog signals are directly routed (via relays) to the 6000’s outputs, thereby bypassing any internal circuitry. Addi-
tionally, the digital input is directly routed to the digital output bypassing the digital receiver. In BYPASS mode the
front panel and remote controls have no effect on the operation of the 6000. In OPERATE mode, when the delay
is active, the incoming signals are processed through the 6000’s analog and digital circuitry, and all front panel
and remote controls are fully functional.
It is recommended that the 6000 remain in the OPERATE mode at all times. Typically, the 6000 would be placed
in the BYPASS mode only if the unit were to malfunction. By design, a loss of mains (AC) power to the 6000 will
force the 6000’s audio bypass relays to route the incoming signal directly to the 6000’s output.
BYPASS status is shown in two places on the 6000. The first is the second line of the home screen on the LCD
display. When in BYPASS mode, the status display line will read “6000 BYPASSED.” The second place is the 7
segment delay display to the right of the LCD display. When in BYPASS mode, this display will read “BYP”.
When the 6000 is in OPERATE mode, the second line of the home screen on the LCD display will show the cur-
rent operational status. It will read “DELAY REMOVED, ADDING DELAY TIME, REDUCING DELAY TIME, WAIT-
ING FOR RELEASE, MUTED, or MAXIMUM DELAY.” The 7 segment delay display will show the current delay as
numerical value.
INPUT/OUTPUT LEVEL (dB) display
The INPUT/OUTPUT LEVEL (dB) provides a visual reference of the input (PRE DELAY) or output (POST DELAY)
signal. There are separate bar graph displays for each of the two channels and appears on the first line of the
home screen in the LCD display. As previously stated, the meters have a range of -40 to 0dBfs. You can use
these meters as a guide to help set the input and output operating level of the 6000. Whatever your input levels
are, fine adjustment of the input signal must be done ahead of the 6000 (typically with the master bus fader of the
broadcast console).
The START button
The START button initiates the gradual increase of delay time. When a radio talk show is to begin, the first action
for the operator of the 6000 is to press the green START button. Once this button has been pressed, it's light will
blink for as long as delay time is increasing. The 7 segment DELAY display on the right end of the LCD screen
displays the amount of time in memory at any given instant. From a starting point of zero delay time, the amount
of time that it takes to achieve the maximum preset delay depends upon the program material and the maximum
delay length set by the user. Once the START button is pressed, assuming no other control button is subse-
quently pressed, the 6000 will proceed to incrementally increase delay time until the maximum preset delay is
achieved.
The EXIT button
The EXIT button initiates the gradual decrease of delay time. Several minutes in advance of the end of a radio talk
show, the operator of the 6000 must press the yellow EXIT button. Once this button is pressed, its light will blink
as long as delay time is decreasing. The 7 segment DELAY display on the right end of the LCD screen displays
the amount of time in memory at any given instant. The amount of time that it takes to reduce the delay time to
zero seconds depends upon the program material and the maximum delay length set by the user. Once the EXIT
button is pressed, assuming no other control button is subsequently pressed, the 6000 will proceed to incremen-
tally decrease delay time until a zero delay time has been reached. Once zero delay has been reached, “DELAY
REMOVED” will be displayed as a status on the second line of the home screen in the LCD display.
4Operation

6000 Broadcast Audio Delay
User’s Guide
PAGE 9
The COUGH button
The COUGH button allows the host to make impromptu interruptions in the program for up to the maximum
amount of time in memory while keeping the audience unaware of the break. When the COUGH button is pushed
and held in, the 6000 plays from memory and mutes incoming audio. As soon as the button is released, the 6000
resumes recording into memory and "splices out" the silence created while the audio was muted. The 6000 then
begins to rebuild the delay time used while the COUGH button was pushed. The host can cough, have a quick
drink of water, or make a comment to the producer or engineer without any perceptible program interruption. If
the COUGH button is pressed for an amount of time exceeding the amount of time in memory, the result will be
muted output audio (dead air).
The DUMP button
The DUMP button should be pressed as soon as an unwanted comment is heard. Once pressed, a length of
audio, as set by the user, in memory is instantly erased. The 6000 will then automatically "splice" around the
erased audio so the audience hears no dead air. Please understand that if the talk show host has not given the
6000 time to build up to enough seconds of delay to cover the audio to be dumped then when he momentarily
hits the DUMP button an obscenity may get on the air. The user has the choice of setting the 6000 to DUMP a
FIFTH, FOURTH, THIRD, HALF or the WHOLE memory.
The 6000 also allows the host extra protection in the form of muting if he purposely holds down the DUMP button.
Holding down the button long enough would erase the entire memory and mute the output of the 6000 until the
DUMP button is released. This provides a "panic button" function for use if all hell breaks loose. The muting func-
tion does not activate when the DUMP button is pushed and quickly released.
After a DUMP command the 6000 automatically reenters the last mode it was in either building or releasing
memory as appropriate.
The A1 through A4 relay status LEDs
The A1 through A4 LEDs show the state of the four internal relays used for delay automation. The LEDs will be off
when the relays are unenergized, green when energized and red when cued to be energized. The pinout for the
DB-25 connector on the rear of the 6000 is in Appendix C. One can use this pinout to build a custom automation
interface or to interface with existing automation or control equipment.
The DELAY time (seconds) display
As previously mentioned, the DELAY time display indicates the time duration of the program audio in the 6000’s
memory at any instant in 0.1 second intervals.

6000 Broadcast Audio Delay
User’s Guide
PAGE 10
Solutions to common problems
There is no output signal.
• Check the AC power connections to the 6000.
• Check input and output cables and connections.
• Determine that there really is a signal coming from the source and that it is getting to the 6000.
Distortion in the digital output signal.
• Check the input signal. Is it overdriving the 6000’s input? If so, the INPUT display should indicate so.
• Is the incoming signal already distorted? Listen "up stream" from the 6000 (or manually place the unit in
BYPASS mode) to determine that you are feeding it a clean signal.
Buzz in the output
• Check input and output connector wiring.
• Check for ground loops between interconnected system equipment.
• Are all system components on the same AC ground?
Noise (hiss)
• Check input signal levels and input level control settings. The input may be too low in level. If so, boost the
signal from your console or input source.
• Is the input signal already noisy? Listen "up stream" from the 6000 to determine if you are feeding it a clean
signal.
Less common problems
The 6000 doesn't power up or doesn't respond properly.
• Consult a qualified service technician or the Symetrix factory.
The 6000 is not plugged in, but works great anyway.
• Consult your doctor or therapist.
5Troubleshooting

6000 Broadcast Audio Delay
User’s Guide
PAGE 11
The AirTools™ Limited Warranty
Symetrix, Inc. expressly warrants that AirTools™ products will be free from defects in material and workman-
ship for eighteen (18) months from the date the product is shipped from the factory. Symetrix's obligations under
this warranty will be limited to repairing or replacing, at Symetrix's option, the part or parts of the product which
prove defective in material or workmanship within eighteen (18) months from the date the product is shipped from
the factory, provided that the Buyer gives Symetrix prompt notice of any defect or failure and satisfactory proof
thereof. Products may be returned by Buyer only after a Return Authorization number (RA) has been obtained
from Symetrix. Buyer will prepay all freight charges to return the product to the Symetrix factory. Symetrix
reserves the right to inspect any products which may be the subject of any warranty claim before repair or
replacement is carried out. Symetrix may, at its option, require proof of the original date of purchase (dated copy
of original retail dealer's invoice). Final determination of warranty coverage lies solely with Symetrix. Products
repaired under warranty will be returned freight prepaid via United Parcel Service by Symetrix, to any location
within the Continental United States. Outside the Continental United States, products will be returned freight col-
lect.
The foregoing warranties are in lieu of all other warranties, whether oral, written, express, implied or
statutory. Symetrix, Inc. expressly disclaims any IMPLIED warranties, including fitness for a particular
purpose or merchantability. Symetrix's warranty obligation and buyer's remedies hereunder are SOLELY
and exclusively as stated herein.
This Symetrix product is designed and manufactured for use in professional and studio audio systems and is not
intended for other usage. With respect to products purchased by consumers for personal, family, or household
use, Symetrix expressly disclaims all implied warranties, including but not limited to warranties of mer-
chantability and fitness for a particular purpose.
This limited warranty, with all terms, conditions and disclaimers set forth herein, shall extend to the original pur-
chaser and anyone who purchases the product within the specified warranty period.
Warranty Registration must be completed and mailed to Symetrix within thirty (30) days of the date of purchase.
Symetrix does not authorize any third party, including any dealer or sales representative, to assume any liability or
make any additional warranties or representation regarding this product information on behalf of Symetrix.
This limited warranty gives the buyer certain rights. You may have additional rights provided by applicable law.
NOTE: Some AirTools™ products contain embedded software and may also be accompanied by control software
intended to be run on a personal computer. Said software is specifically excluded from this warranty.
Limitation of Liability
The total liability of Symetrix on any claim, whether in contract, tort (including negligence) or otherwise arising
out of, connected with, or resulting from the manufacture, sale, delivery, resale, repair, replacement or use of any
product will not exceed the price allocatable to the product or any part thereof which gives rise to the claim. In no
event will Symetrix be liable for any incidental or consequential damages including but not limited to damage for
loss of revenue, cost of capital, claims of customers for service interruptions or failure to supply, and costs and
expenses incurred in connection with labor, overhead, transportation, installation or removal of products, substi-
tute facilities or supply houses.
6Warranty and Service

6000 Broadcast Audio Delay
User’s Guide
PAGE 12
Servicing the 6000
If you have determined that your 6000 requires repair services and you live outside of the United States please
contact your local AirTools™ dealer or distributor for instructions on how to obtain service. If you reside in the U.S.
then proceed as follows.
Return authorization
At the Symetrix factory, Symetrix will perform in-warranty or out-of-warranty service on any product it has manu-
factured for a period of three years from date of manufacture.
Before sending anything to Symetrix, please contact our Customer Service Department for a return authoriza-
tion (RA) number. The telephone number is [phone]. Additionally, support is available via E-mail through
[email protected] or via the web site http://www.airtoolsaudio.com.
In-warranty repairs
To get your 6000 repaired under the terms of the warranty:
1. Call us for an RA number (have your serial number, contact information and description of the problem handy).
2. Pack the unit in its original packaging materials.
3. Include your name, address, daytime telephone number, and a brief statement of the problem.
4. Write the RA number on the outside of the box.
5. Ship the unit to Symetrix, freight prepaid. We do not accept freight collect shipments.
Just do these five things, and repairs made in-warranty will cost you only one way freight charges. We'll pay the
return freight.
If you don't have the factory packaging materials, we recommend using an oversize box. Wrap the unit in a plastic
bag, surround it with bubble-wrap, and place it in the box surrounded by Styrofoam peanuts. Be sure there is
enough clearance in the box to protect the rack ears. We won't return the unit in anything but Symetrix packag-
ing for which we will have to charge you. If the problem is due to operator misuse or error, you will have to pay for
both parts and labor. In any event, if there are charges for the repair, you will pay for the return freight. All charges
will be COD unless you have made other arrangements (prepaid, Visa or Mastercard).
Out-of-warranty repairs
If the warranty period has passed, you'll be billed for all necessary parts, labor, packaging materials, and freight
charges. Please remember, you must call for an RA number before sending the unit to Symetrix. Please have
your payment information available as well as all information required under Item 1, In-warranty repairs when call-
ing for an RA number.

6000 Broadcast Audio Delay
User’s Guide
PAGE 13
Architects and engineers specifications
The Broadcast Audio Delay shall be a stereo model whose output is delayed by as much as 40 seconds, thereby
allowing the operator to delete or "dump" unwanted audio. The Broadcast Audio Delay shall occupy one rack
space (1U).
The inputs shall be active balanced bridging designs terminated with 3-pin XLR (AES/IEC standard wiring) female
jacks.
The outputs shall be active balanced designs terminated with 3-pin XLR (AES/IEC standard wiring) male jacks.
Overall frequency response shall be 20 Hz to 20 kHz, +/- 1 dB, measured at +4 dBu output. There shall be no
more than 0.01% harmonic distortion measured under the following conditions: +4 dBu input, +4 dBu output, 40
second delay, 1000 Hz test frequency.
When the unit is inoperative (either by loss of power, or via the BYPASS switch), the inputs and outputs shall be
wired together.
The Broadcast Audio Delay shall be capable of operating by means of its own built-in power supply connected to
100-240 VAC, 50-60 Hz, 25 W.
The Broadcast Audio Delay shall be a Symetrix, Incorporated model 6000 BROADCAST AUDIO DELAY.
Technical specifications
Input/Output Connectors
Inputs stereo, balanced bridging
Outputs stereo, electronically balanced
Input Connectors XLR
Output Connectors XLR
Polarity Pin 2 high
Maximum Input Level +28 dBu
Maximum Output Level +28 dBu into 100k ohms
Input Common Mode Rejection >40 dB @ 1 kHz
Performance Data
Frequency Response 20 Hz to 20 kHz*, +/- 1dB at +4dBu output
Harmonic Distortion less than 0.01% with +4dBu input, +4dBu output, 40 second
delay and a 1 kHz test frequency
Typical Dynamic Range
A/D -110 dB (A-weighted)
D/A -115 dB (A-weighted)
A/D and D/A Conversion 24-bit sigma delta
Internal Sampling Rate 48 kHz
External Digital Sync Range 30 to 50 kHz, AES and Word Clock
Physical
Size (HWD) 1.72 in. x 19 in. x 8.2 in. plus connectors
4.37 cm x 48.30 cm x 17.145 cm
Shipping Weight 8 lbs, 3.64 kg
Electrical
Power Requirements 100 VAC to 240 VAC, 50 Hz to 60 Hz, 25 W
*A high pass filter is engaged during build and exit modes only when using the gap detect or gap detect+catchup
algorithms. During build and exit modes when using either of these algorithms, the frequency response will be
down about -3 dB at 100 Hz.
ASpecifications
Appendix

6000 Broadcast Audio Delay
User’s Guide
PAGE 14
Many of the 6000’s most important control buttons and LED indicators may be wired to a user supplied panel
via the DB-25 multi-pin male connector on the 6000’s rear panel. The following tables detail the pin functions.
The remote switches and LED indicators are electrically isolated from the switches and LEDs on the 6000’s front
panel, but effectively operate in parallel (i.e. simultaneously) with them. The AirTools RC-6000 is also available to
directly interface to this port and provide all of the functions detailed in this pinout.
Remote panel switch pinouts
Function Pin #
START 1
EXIT 4
DUMP 7
COUGH 10
BYPASS (Hardware) 14
Switch Common 13
Remote panel LED indicator pinouts
Function LED Cathode LED Anode
HALF pin 3 pin 2
WHOLE pin 6 pin 5
START pin 9 pin 8
EXIT pin 12 pin 11
DUMP pin 16 pin 15
COUGH pin 18 pin 17
DELAY INACTIVE pin 20 pin 19
DELAY ACTIVE pin 22 pin 21
BRemote Indicator & Control Interface wiring
Appendix
Note: The remote switches used should be high
quality, momentary, single pole, push button
type. All switches should return to pin #13, the
switch common point.
Note: The BYPASS switch can be either a
momentary or toggle. If the switch is on for
more than a half second, it is treated as a toggle
switch and the 6000 will be forced into BYPASS
no matter the current bypass state. Shorter acti-
vation results in a bypass on/off toggle.
Note: Within the 6000, all LED anodes connect
to +5V through 220 ohm resistors and all LED
cathodes are grounded. No external resistors
are required.
HALF indicates that at least half of the set delay
has been built.
WHOLE indicates that the whole set amount of
delay is built.
START, EXIT, DUMP and COUGH exactly mirror
the respective buttons/indicators on the front of
the unit.
Note: Pin 19 (DELAY INACTIVE) will have +5V
when the current delay = 0.0 seconds.
Pin 21 (DELAY INACTIVE) will have +5V when
the current delay is greater than 0.0 seconds.

6000 Broadcast Audio Delay
User’s Guide
PAGE 15
Typical remote panel switch wiring
Typical remote panel LED wiring
Note: The numbers within the circles refer to pins on the 6000’s rear panel DB-25 connector which is labelled
REMOTE INDICATOR & CONTROL INTERFACE.
COUGH
DUMP
EXIT
START
13
1
4
7
10
3 6 12 9 16 18
152 5 11 8 17
WHOLEHALF EXIT START DUMP COUGH

6000 Broadcast Audio Delay
User’s Guide
PAGE 16
CAutomation wiring
Appendix
Automation connector pinout
Function Pin #
Relay 1 Common 1
Normally Closed 2
Normally Open 3
Relay 2 Common 4
Normally Closed 5
Normally Open 6
Relay 3 Common 7
Normally Closed 8
Normally Open 9
Relay 4 Common 10
Normally Closed 11
Normally Open 12
LED 1 (A1) 13
LED 2 (A2) 14
LED 3 (A3) 15
LED 4 (A4) 16
LED Return 17
Auto In 1 18
Auto In 2 19
Auto In 3 20
Auto In 4 21
Auto In Ground 22
Automation
Button
Closures